Vacuum insulated apparatus with darkly colored core insulation material and method of making the same
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vacuum insulated apparatuses, such as refrigerators, face a challenge with carbon black increasing solid conductivity while attempting to decrease radiative conductivity, due to its large particle size and non-porous nature, counteracting the low solid conductivity benefits of fumed silica.
Innovation Solution
Incorporating first particles like fumed silica with second particles or molecules coated onto or bonded to them, using Van der Walls, hydrogen, or covalent bonding to impart a dark color and low radiative thermal conductivity, while maintaining low solid conductivity, without significantly increasing particle size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If carbon black particles are used to reduce radiative conductivity, then radiative thermal conductivity decreases, but particle size increases
Solution Approach 1:
The patent structures the insulation material as nested particles where carbon black particles are coated onto or bonded to the surface of fumed silica particles. This nesting arrangement allows the carbon black to provide radiative heat blockage while the underlying silica particle maintains the small overall particle size, preventing significant increase in particle dimensions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The resulting core insulation material exhibits a dark color with reduced total thermal conductivity, effectively addressing the conductivity imbalance and enhancing insulation performance.
Implementation Method 1
the second particles or molecules are coated onto or bonded to the first particles via Van der Walls forces, hydrogen bonding, ionic bonding, or covalent bonding
Implementation Method 2
the second particles or molecules are coated onto or bonded to the first particles via Van der Walls forces, hydrogen bonding, ionic bonding, or covalent bonding
Implementation Method 3
the second particles or molecules are coated onto or bonded to the first particles via Van der Walls forces, hydrogen bonding, ionic bonding, or covalent bonding
Implementation Method 4
the second particles or molecules are coated onto or bonded to the first particles via Van der Walls forces, hydrogen bonding, ionic bonding, or covalent bonding
Implementation Method 5
carbon black is thought to decrease radiative conductivity of thermal radiation through the insulative structure because carbon black has a dark color and a high extinction coefficient
Implementation Method 6
The fumed silica is thought to decrease solid conductivity of heat through the insulative structure because particles of fumed silica are small and porous
Data Source
AI summary
A vacuum insulated apparatus including (a) an insulative structure with a sealed interior volume having a pressure of less than atmospheric pressure and (b) core insulation material disposed within the sealed interior volume, the core insulation material exhibiting a dark color and comprising (i) first particles and (ii) second particles or molecules coated onto or bonded to the first particles. The core insulation material exhibits CIELAB color space coordinates having an L* value within a range of from 0 to 40. The first particles can be fumed silica. The second particles or molecules can be dye particles or molecules. The first particles and the second particles or molecules can have opposite charges. The vacuum insulated structure can be a component of a refrigeration appliance, a dewar for liquid nitrogen, among other things.